Desire for happiness coupled with understanding of karma is the whole practice

"Every time we chant the five themes for daily recollection, I’m struck by the contrast between that chant and the one that follows it: “May I be happy.”

The themes for recollection are not happy things. We’re subject to aging, subject to illness, subject to death, subject to separation. And even the principle of karma, which is what the Buddha offers as hope in our practice, still sounds pretty onerous. You slip up and you’re going to suffer.

And then we chant, “May I be happy.”

That contrast right there says a lot about life. We live in a world where there’s a lot of suffering. In addition to the basic suffering that comes from having a body, there are also all the horrible things that people do to one another: killing, stealing, cheating, abusing in one way or another.

Yet in the midst of all this, we want happiness. It’s this desire for happiness that underlies the whole practice, coupled with an understanding of karma: Without that understanding, the desire for happiness becomes sentimental and sometimes rather unrealistic. But as the principle of karma says, if you act with skillful intentions, the results will be happy, the results will be pleasant.

This means we have to act with skillful intentions, intentions that don’t want to cause harm. It’s that desire not to cause harm and the realization that we have to implement it through the principle of karma: That’s the beginning of the practice. It’s the motivation and the understanding.

This is the beginning of what are sometimes called the wisdom and compassion — more appropriately the discernment and goodwill — that underlie the practice. That’s what starts us out. It’s why we chant these things every day.

Now, for most of us, our desire for happiness in a world where there is a lot of suffering often leads us to harden ourselves. We’ve suffered from this person, that person, this kind of thing, that kind of thing. We harden ourselves both inside and out, hoping that that’s the way to get out of suffering.

But it doesn’t work that way. The more you harden yourself, the more insensitive you get to your actions. And it’s through your actions that you have your only hope for getting out of this predicament we’re all in.

So one of the first steps in the practice is to begin to soften yourself up from the inside — not only with thoughts of goodwill [mettā], but also actual actions showing goodwill for yourself.

You start with a very immediate way, the way you breathe."

~ Thanissaro Bhikkhu "Desire for Happiness"